Revisiting adult neurogenesis and the role of erythropoietin for neuronal and oligodendroglial differentiation in the hippocampus

Recombinant human erythropoietin (EPO) improves cognitive performance in neuropsychiatric diseases ranging from schizophrenia and multiple sclerosis to major depression and bipolar disease. This consistent EPO effect on cognition is independent of its role in hematopoiesis. The cellular mechanisms of action in brain, however, have remained unclear. Here we studied healthy young mice and observed that 3-week EPO administration was associated with an increased number of pyramidal neurons and oligodendrocytes in the hippocampus of ~20%. Under constant cognitive challenge, neuron numbers remained elevated until >6 months of age. Surprisingly, this increase occurred in absence of altered cell proliferation or apoptosis. After feeding a ¹⁵N-leucine diet, we used nanoscopic secondary ion mass spectrometry, and found that in EPO-treated mice, an equivalent number of neurons was defined by elevated ¹⁵N-leucine incorporation. In EPO-treated NG2-Cre-ERT2 mice, we confirmed enhanced differentiation of preexisting oligodendrocyte precursors in the absence of elevated DNA synthesis. A corresponding analysis of the neuronal lineage awaits the identification of suitable neuronal markers. In cultured neurospheres, EPO reduced Sox9 and stimulated miR124, associated with advanced neuronal differentiation. We are discussing a resulting working model in which EPO drives the differentiation of non-dividing precursors in both (NG2+) oligodendroglial and neuronal lineages. As endogenous EPO expression is induced by brain injury, such a mechanism of adult neurogenesis may be relevant for central nervous system regeneration.

The perimetric boycott: a tool for tobacco control advocacy

OBJECTIVES

To propose criteria to help advocates: (1) determine when tobacco related boycotts may be useful; (2) select appropriate targets; and (3) predict and measure boycott success.

METHODS

Analysis of tobacco focused boycotts retrieved from internal tobacco industry documents websites and other scholarship on boycotts.

RESULTS

Tobacco related boycotts may be characterised by boycott target and reason undertaken. Most boycotts targeted the industry itself and were called for political or economic reasons unrelated to tobacco disease, often resulting in settlements that gave the industry marketing and public relations advantages. Even a lengthy health focused boycott of tobacco industry food subsidiaries accomplished little, making demands the industry was unlikely to meet. In contrast, a perimetric boycott (targeting institutions at the perimeter of the core target) of an organisation that was taking tobacco money mobilised its constituency and convinced the organisation to end the practice.

CONCLUSIONS

Direct boycotts of the industry have rarely advanced tobacco control. Perimetric boycotts of industry allies offer advocates a promising tool for further marginalising the industry. Successful boycotts include a focus on the public health consequences of tobacco use; an accessible point of pressure; a mutual interest between the target and the boycotters; realistic goals; and clear and measurable demands.

From adversary to target market: the ACT-UP boycott of Philip Morris

BACKGROUND

In 1990, the AIDS Coalition to Unleash Power (ACT-UP) sparked a year long boycott of Philip Morris's Marlboro cigarettes and Miller beer. The boycott protested the company's support of Senator Jesse Helms (R-North Carolina), a leading opponent of AIDS funding and civil rights for lesbian, gay, bisexual and transgender (LGBT) people. ACT-UP demanded that Philip Morris sever its ties with Helms and acknowledge its responsibility to the LGBT community and to people with AIDS.

OBJECTIVE

To assess the impact of the boycott on the LGBT community, the tobacco industry, and the tobacco control movement; and to determine what lessons tobacco control advocates can extract from this case.

DATA SOURCES

Internal tobacco industry documents and newspaper archives.

METHODS

Search of tobacco industry documents websites using "boycott", "ACT-UP", "gay", and other terms.

RESULTS

Philip Morris used the boycott to its own advantage. It exploited differences within the community and settled the boycott by pledging large donations to combat AIDS. Through corporate philanthropy, Philip Morris gained entrée to the LGBT market without appearing gay friendly. Many LGBT organisations, thirsty for recognition and funding from mainstream corporations, welcomed Philip Morris's overtures without considering the health hazards of tobacco.

CONCLUSIONS

Unless the goal of a boycott is to convince the tobacco industry to abandon tobacco altogether, such actions invite the industry to expand its marketing under the guise of philanthropy. Tobacco control advocates should be clear about goals and acceptable settlement terms before participating in a boycott of a tobacco company.